Introduction to Anatomy & Physiology

Characteristics and Organization of Living Organisms

• Common Characteristics: All living organisms share features such as cellular organization, metabolism, growth, responsiveness, reproduction, and homeostasis.

• Levels of Structural Organization: The human body is organized hierarchically: chemical, cellular, tissue, organ, organ system, and organism levels.

• Body Systems: The body consists of multiple systems (e.g., circulatory, respiratory, nervous), each with specific organs and functions.

• Anatomy vs. Physiology: Anatomy is the study of body structure; physiology is the study of body function.

Anatomical Position and Terminology

• Anatomical Position: Standard reference position: standing, facing forward, arms at sides, palms forward.

• Directional Terms: Used to describe locations (e.g., anterior/posterior, superior/inferior, medial/lateral).

• Planes of Section: Sagittal, frontal (coronal), and transverse planes divide the body for study.

Body Cavities and Membranes

Organization of Body Cavities

• Major Cavities: Dorsal (cranial and vertebral) and ventral (thoracic and abdominopelvic) cavities house organs.

• Serous Membranes: Line body cavities and cover organs; include pleura, pericardium, and peritoneum.

Homeostasis and Feedback Mechanisms

Homeostasis

• Definition: Maintenance of a stable internal environment despite external changes.

• Feedback Loops: Negative feedback reduces deviation from a set point (e.g., body temperature regulation); positive feedback amplifies changes (e.g., blood clotting).

• Components: Receptor, control center, effector.

Chemistry of Life

Atoms, Ions, and Molecules

• Atoms: Smallest units of matter; consist of protons, neutrons, electrons.

• Ions: Charged atoms (cations: positive, anions: negative).

• Electrolytes: Substances that dissociate into ions in solution, conducting electricity.

Compounds and Chemical Bonds

• Molecules: Two or more atoms bonded together.

• Compounds: Molecules composed of different elements.

• Chemical Bonds: Ionic, covalent, and hydrogen bonds.

• Organic vs. Inorganic Compounds: Organic compounds contain carbon-hydrogen bonds; inorganic do not.

Water and pH

• Properties of Water: Polarity, cohesion, high heat capacity, solvent abilities.

• pH Scale: Measures hydrogen ion concentration; .

• Buffers: Substances that minimize pH changes.

Macromolecules

• Carbohydrates: Energy source; monosaccharides, disaccharides, polysaccharides.

• Lipids: Fats, oils, phospholipids, steroids; energy storage, membrane structure.

• Proteins: Polymers of amino acids; structure, enzymes, signaling.

• Nucleic Acids: DNA and RNA; genetic information storage and transfer.

ATP and Cellular Energy

• ATP (Adenosine Triphosphate): Main energy currency of the cell.

• Hydrolysis of ATP:

Cell Structure and Function

Cell Components

• Plasma Membrane: Phospholipid bilayer with proteins; regulates entry/exit of substances.

• Organelles: Nucleus, mitochondria, endoplasmic reticulum, Golgi apparatus, lysosomes, etc.

• Cytoplasm: Cytosol and organelles between nucleus and membrane.

Transport Mechanisms

• Diffusion: Movement of molecules from high to low concentration.

• Osmosis: Diffusion of water across a semipermeable membrane.

• Active Transport: Movement against concentration gradient using energy (e.g., sodium-potassium pump).

• Vesicular Transport: Endocytosis and exocytosis for bulk movement.

Cell Division

• Mitosis: Division of somatic cells for growth and repair.

• Meiosis: Division for gamete production (not detailed in this guide).

Tissues

Histology and Tissue Types

• Histology: Study of tissues.

• Primary Tissue Types: Epithelial, connective, muscle, nervous.

• Extracellular Matrix: Non-cellular material providing support and structure.

Epithelial Tissue

• Characteristics: Covers surfaces, lines cavities, forms glands; avascular, high regeneration.

• Cell Junctions: Tight, adherens, desmosomes, gap junctions.

• Classification: By cell layers (simple, stratified) and shape (squamous, cuboidal, columnar).

Connective Tissue

• Functions: Support, protection, transport, storage.

• Types: Loose, dense, cartilage, bone, blood.

• Components: Cells (fibroblasts, adipocytes, etc.), fibers (collagen, elastic, reticular), ground substance.

Muscle and Nervous Tissue

• Muscle Tissue: Skeletal (voluntary movement), cardiac (heart), smooth (walls of organs).

• Nervous Tissue: Neurons (signal transmission), neuroglia (support).

Integumentary System

Structure and Function

• Components: Skin, hair, nails, glands.

• Skin Layers: Epidermis (outer), dermis (middle), hypodermis (subcutaneous).

• Functions: Protection, temperature regulation, sensation, vitamin D synthesis.

Skin Color and Accessory Structures

• Pigmentation: Melanin, carotene, hemoglobin.

• Accessory Structures: Hair (structure, growth, color), nails (structure, function), glands (sebaceous, sweat).

Skin Disorders and Repair

• Burns: Classified by depth (first, second, third degree); rule of nines estimates surface area.

• Tissue Repair: Involves inflammation, proliferation, and remodeling phases.

Skeletal System

Bone Structure and Function

• Functions: Support, protection, movement, mineral storage, blood cell formation.

• Classification: Long, short, flat, irregular bones.

• Bone Tissue: Compact and spongy bone; osteons, trabeculae.

• Bone Growth and Remodeling: Involves osteoblasts (build bone), osteoclasts (break down bone), and hormonal regulation.

• Fractures: Types include simple, compound, comminuted, greenstick, etc.

Table: Comparison of Tissue Types

Additional info:

• Some details (e.g., specific examples, certain definitions) were expanded for clarity and completeness.

• For a full understanding, students should refer to their course textbook and lecture materials.